Techniques for reducing luminance unevenness and color unevenness of an image (video) projected onto a projection plane by a projection type projector apparatus have been developed.
For example, Patent Literature 1 discloses a technique of reducing the luminance unevenness and color unevenness of a projected image (video) by correcting the image (video) in projecting the image using a projection type projector apparatus in consideration of the reflection characteristics of the projection plane.
The technique of Patent Literature 1 (Japanese Unexamined Patent Publication No. 2012-28877) measures a luminance value of each color component for each pixel of a captured image obtained by capturing a projected image, and then calculates a light distribution map, which indicates a change rate of luminance with respect to a luminance reference point in a video, based on a luminance value of each color component for each measured pixel. The technique of Patent Literature 1 then normalize the measured luminance value of each color component for each pixel using the light distribution map to calculate a response function, and corrects the luminance value of each color component for each pixel in the inputted video signal using the response function and the light distribution map to obtain a corrected video signal. The technique of Patent Literature 1 then projects the corrected video signal onto the projection plane.